In the 80s/90s, always just one in the living room. And just the 4 channels no cable/sky. We had loads of vhs tapes though.
Never had a tv in my bedroom and still now we only have one in the living room. Teens have their laptops but mostly if we watch tv it's on the big one. And we switch it on to watch something specific then off again when it's finished. Always have done. Find it very odd the idea of leaving the telly on all the time.